Going back several months there was active support for Google's Android on Wayland. A Collabora employee created a Weston back-end for Android, which after weeks of work, was running on a Google Nexus phone.
Since then, the Android back-end really hasn't seen much love. Google hasn't officially expressed any interest in switching over to Wayland for Android and Pekka Paalanen has moved onto other Wayland work. Paalanen has decided that it's simply time to drop this back-end from Weston.
The Android backend has been fairly unused, since we do not have projects actively using it. It gets basic build testing as part of the normal build, but runtime testing it takes a considerable effort, and so I have not done that in a long time. The code is slowly rotting, and with new emerging backends it starts to be a burden, since it cannot use udev, but needs evdev.The Android back-end was killed today in Git as confirmed by Kristian.
Therefore to ease Weston going forward, remove the Android backend. If someone misses it, it can still be found in the stable 1.0 branch, and of course resurrected from git history if someone wants to put in the effort and maintain it.